\documentclass[a4paper,fontset=none]{ctexart}
\usepackage{tikz}
\usepackage{pgfplots}
\pgfplotsset{compat=1.18}
\usepackage{xeCJK}
\setCJKmainfont{STSong} 


\begin{document}
\begin{figure}[htbp]
\centering
\begin{tikzpicture}
\begin{axis}
        [
        axis lines = middle,
        xlabel = $x$,
        ylabel = $y$,
        xtick={0,pi/2,pi,3*pi/2,2*pi},
        xticklabels={$0$,$\frac{\pi}{2}$,$\pi$,$\frac{3 \pi}{2}$ ,$2\pi$},
        xmin=-0.5,
        xmax=2*pi + 0.5,
        ymin=-1.2,
        ymax=1.2,
        ytick=\empty,
        axis line style={line width=2pt},
        tick style={line width=2pt}
    ]
    \addplot[domain=0:2*pi, samples=100, line width=2pt] {sin(deg(x))};
\end{axis}
\end{tikzpicture}
\caption{正弦图像}
\end{figure}

\begin{figure}[htbp]
\centering
\begin{tikzpicture}
    \begin{axis}
            [
            axis lines = middle,
            xlabel = $x$,
            ylabel = $y$,
            xtick={0,pi/2,pi,3*pi/2,2*pi},
            xticklabels={$0$,$\frac{\pi}{2}$,$\pi$,$\frac{3 \pi}{2}$ ,$2\pi$},
            xmin=-0.5,
            xmax=2*pi + 0.5,
            ymin=-1.2,
            ymax=1.2,
            ytick=\empty,
            axis line style={line width=2pt},
            tick style={line width=2pt}
        ]
        \addplot[domain=0:2*pi, samples=100, line width=2pt] {cos(deg(x))};
        \addplot[domain=0:2*pi, samples=100, line width=2pt, color=red] {tan(deg(x))};
    \end{axis}
\end{tikzpicture}
\caption{余弦图}
\end{figure}


\end{document}